Sleeve lubricating method and sleeve lubricating mechanism

ABSTRACT

A sleeve lubricating mechanism which is able to positively coating a powder lubricant onto an inside surface of a molten metal feeding sleeve for a vertical shot casting machine. This mechanism is composed of an attachment which contacts with a molten metal feeding port of the sleeve to block it so as to bring a sleeve inside to a closed condition, a vacuum device sucking air from the sleeve inside through the attachment, and a powder feeding device discharging the powder lubricant together with air from a nozzle into the sleeve inside through the attachment.

BACKGROUND OF THE INVENTION

This invention relates to a sleeve lubricating method and a sleevelubricating mechanism, in which a powder lubricant is coated on aninside surface of a molten metal feeding sleeve for a vertical shotcasting machine.

Water dispersion of graphite or inorganic substance (such as talc, micaetc.) has conventionally been used for a lubricant. This waterdispersion has been sprayed onto the inside surface of the molten metalfeeding sleeve for the vertical shot casting machine, while verticallymoving an atomizer and an air blow nozzle attached to a drive device. Inother words, the water dispersion has been sprayed from the atomizer,and moisture of the sprayed water dispersion has been removed by the airblow nozzle.

However, the above method spraying the lubricant forming the waterdispersion has included the following problems.

(a) The lubricant has been scattered to stain places around the sleeve.Especially, the graphite water dispersion has caused a worse workingenvironment.

(b) High air blow noise emitted when removing moisture and requiring anoperator to have a soundproof device on, have caused a worseworkability.

(c) Clogged atomizer and air blow nozzle unable to coat the lubricantuniformly, have probably induced to ununiformity of product quality.

In order to eliminate the troubles induced by using the water dispersionfor the lubricant, use of a powder lubricant has been tried. However, ithas been difficult to positively coat the powder lubricant onto theinside surface of the sleeve.

BRIEF SUMMARY OF THE INVENTION

A first object of this invention is to provide a sleeve lubricatingmethod which is able to positively coat the powder lubricant onto theinside surface of the molten metal feeding sleeve for the vertical shotcasting machine.

A second object of this invention is to provide a sleeve lubricatingmechanism which is able to put the foregoing sleeve lubricating methodinto practice.

In order to accomplish the above first object, the sleeve lubricatingmethod of this invention is a method for coating the powder lubricantonto the inside surface of the molten metal feeding sleeve for thevertical shot casting machine, comprising an attachment setting processin which a molten metal feeding port of the sleeve is blocked by theattachment to bring a sleeve inside to a closed condition, and a coatingprocess in which the powder lubricant is discharged together with air bya powder feeding device from the nozzle into the sleeve inside throughthe attachment, while sucking air from the sleeve inside by a vacuumdevice through the attachment.

According to the sleeve lubricating method of this invention, since thepowder lubricant is discharged from the nozzle in the coating processwhile reducing pressure from the sleeve inside, the powder lubricant iseasily dispersed widely in the sleeve inside to reach every corners ofsleeve inside and adhere thereto. Consequently, a preferable lubricationeffect can be obtained in a molten metal feeding work.

Further, since the powder lubricant is discharged from the nozzle intothe sleeve inside under the pressure reduced condition, the clogging ofthe powder lubricant at the nozzle can be avoided. Therefore, the powderlubricant can be coated positively, the desired lubrication effect canalways be obtained, and a quality of cast product can be stabilized.

In addition, since the coating process is carried out under the closedcondition, air noise is prevented from emitting outside and placesaround the sleeve can be prevented from being stained.

In the sleeve lubricating method of this invention, the followingconstructions may be used.

(1) In the coating process, a protruding length of the nozzle into thesleeve inside is set to a prescribed value. According to thisconstruction, an adhering degree of the powder lubricant onto the insidesurface of sleeve can be adjusted.

(2) In the coating process, a sucking force of the vacuum device and anair discharging pressure and capacity of the powder feeding device canbe set to prescribed values. According to this construction, the processcan be adapted to various work conditions.

In order to accomplish the above second object, the sleeve lubricatingmechanism of this invention is a mechanism for coating the powderlubricant onto the inside surface of the molten metal feeding sleeve forthe vertical shot casting machine, comprising the attachment whichcontacts with a molten metal feeding port of the sleeve to block it soas to bring the sleeve inside to a closed condition, the vacuum devicesucking air from the sleeve inside through the attachment, and thepowder feeding device discharging the powder lubricant together with airfrom the nozzle into the sleeve inside through the attachment.

According to the sleeve lubricating mechanism of this invention, thesleeve lubricating method of this invention can be put into practice bya simple construction.

In the sleeve lubricating mechanism of this invention, the followingconstruction may be used further.

(3) The nozzle secured to the attachment is composed of a copper pipewhose length can be adjusted by being cut. According to thisconstruction, the above construction (1) can be put into practice by asimple work.

(4) The sucking force of the vacuum device and the discharge pressureand capacity of the powder feeding device can be adjusted. According tothis construction, the above construction (2) can be put into practice.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a vertical sectional view showing a state where the sleevelubricating mechanism of this invention is applied to the molten metalfeeding sleeve for the vertical shot casting machine.

FIG. 2 is a flow chart showing a work process of the sleeve lubricatingmechanism of this invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is the vertical sectional view showing the state where the sleevelubricating mechanism of this invention is applied to the molten metalfeeding sleeve for the vertical shot casting machine. The sleevelubricating mechanism of this invention is composed of an attachment 1,a vacuum device 2 and a powder feeding device 3.

The attachment 1 is installed in such a way that it can move in bothlateral and vertical directions by a drive device 6, and contacts with amolten metal feeding port 41 of a sleeve 4 to block it so as to bring aninside of the sleeve 4 to a closed condition. A plunger tip 5 fits inthe sleeve 4 freely slidingly from under side. The attachment 1 isformed into a thick disk-shape having a double structure comprising abody section 11 and a contacting section 12. The body section 11 is madeof aluminum and the contacting section 12 is made of silicon rubber, anda contacting part 121 of the contacting section 12 with the molten metalfeeding port 41 is formed into a tapered shape.

The vacuum device 2 is a device which sucks air from an inside of thesleeve 4 through the attachment 1. A sucking force is made adjustable. Asucking passage 21 is formed in and piercing through the attachment 1.

The powder feeding device 3 is a device which discharges the powderlubricant together with air from a nozzle 31. An air discharge pressureand its capacity are made adjustable. The nozzle 31 is made of a copperpipe and so installed as to protrude downward from the contactingsection 12 of the attachment 1. The nozzle 31 is adjustable in itslength to a voluntary value by cutting the copper pipe. A dischargepassage 32 connecting to the nozzle 31 is formed in and piercing throughthe attachment 1.

A function of the sleeve lubricating mechanism having the abovestructure, i.e. the sleeve lubricating method of this invention, will bedescribed hereunder. FIG. 2 is the flow chart showing the work processof the sleeve lubricating mechanism.

When the sleeve 4 is set to a molten metal feeding position (process i),the attachment 1 is first moved in lateral direction by the drive device6 (process ii). When it comes just above the sleeve 4, its movement isstopped (process iii).

Then, downward movement of the attachment 1 is commenced (process iv),and the powder feeding device 3 is operated to let air blow from thenozzle 31 (process v).

In the next stage, when the attachment 1 contacts with the molten metalfeeding port 41 of the sleeve 4, the downward movement of the attachment1 is stopped (process vi). Then, the discharging of the powder lubricantfrom the nozzle 31 is commenced (process vii), and at the same time thevacuum device 2 is operated (process viii).

In the next stage, when a specified quantity of the powder lubricant hasbeen discharged, the discharging of the powder lubricant is completed(process ix) and at the same time or later the operation of the vacuumdevice 2 is stopped (process x).

In the next stage, the attachment 1 is moved upward and then in thelateral direction (processes xii to xv). Molten metal is poured from themolten metal feeding port 41 into the sleeve 4 (process xvi), so that anordinary molten metal feeding work, i.e. a casting work, is carried out(process xvii). Reverse cleaning blow work is carried out by the powderfeeding device 3 at a voluntary set time (process xi).

According to the foregoing sleeve lubricating method, in the coatingprocess described in the processes vii to x, the powder lubricant isdischarged from the nozzle 31 while reducing pressure from the inside ofthe sleeve 4 by the vacuum device 2. Therefore, the powder lubricant isscattered easily and widely in the sleeve 4 and comes to every cornersand adheres thereto in the sleeve 4. Consequently, a preferablelubrication effect can be provided in the molten metal feeding workcarried out by sliding the plunger tip 5.

Since the powder lubricant is discharged from the nozzle 31 into theinside of the sleeve 4 under the pressure reduced condition, the powderlubricant is prevented from clogging at the nozzle 31. Consequently, thepowder lubricant is coated positively, the desired lubrication effect isalways obtained and the quality of cast product is stabilized.

Since the coating process described in the processes vii to x, iscarried out under the closed condition, air noise is scarcely emittedoutside and places around the sleeve 4 are not stained.

Since the nozzle 31 is adjustable in its length, the degree of adhesionof the powder lubricant onto the inside surface of the sleeve 4 can beadjusted.

Further, since the sucking force of the vacuum device 2 and the airdischarge pressure and capacity of the powder feeding device 3 can beset to voluntary values, the coating process can be adapted to variousworking conditions.

Table 1 shows results comparing the method of this invention and theconventional method. The sleeve lubricating method of this invention isas described above, and the conventional sleeve lubricating method is asdescribed below. While the atomizer and air blow nozzle attached to thedrive device are moved in vertical direction, the graphite waterdispersion is sprayed from the atomizer onto the inside surface of thesleeve, so that the moisture of the water dispersion is removed by theair blow nozzle.

                  TABLE 1                                                         ______________________________________                                                        Conventional                                                                            Method of                                           Results of comparison                                                                         method    this invention                                      ______________________________________                                        Stain preventing                                                                              x         ∘                                       effect around sleeve                                                          Air noise preventing                                                                          x         ∘                                       effect                                                                        Quality stabilizing                                                                           x         ∘                                       effect                                                                        Lubridation effect                                                                            ∘                                                                           ∘                                       ______________________________________                                         ∘ . . . Good, x . . . Bad                                    

As obvious from Table 1, according to the method of this invention, thestain preventing effect, air noise preventing effect and the qualitystabilizing effect are superior to those of the conventional method.

We claim:
 1. A lubrication method for a molten metal feeding sleeve of avertical shot casting machine, the method comprising the acts of:movingan attachment into a position in contact with and closing-off a moltenmetal feeding port opening of the sleeve to form a closed interior ofthe sleeve; suctioning air via an air passage extending through theattachment from the interior of the sleeve via the molten metal feedingport opening with a vacuum device; and discharging both powder lubricantand air from a nozzle extending into the interior of the sleeve throughthe molten metal feeding port opening via a passage extending throughthe attachment to coat the interior of the sleeve with the powderlubricant.
 2. A sleeve lubricating method as set forth in claim 1, inwhich a protruding length of the nozzle into the sleeve inside is set toa prescribed value in the coating process.
 3. A sleeve lubricatingmethod as set forth in claim 1, in which a sucking force of the vacuumdevice and an air discharging pressure and capacity of the powderfeeding device are set to prescribed values in the coating process.
 4. Alubricating system in a vertical shot casting machine, comprising:amolten metal feeding sleeve of the vertical shot casting machine, thefeeding sleeve having a single molten metal feeding port opening; anattachment sized to contact and close-off the single molten metalfeeding port opening to provide a closed interior within the feedingsleeve; a vacuum device having a passage extending through theattachment to suck air from the interior of the sleeve through thesingle molten metal feeding port opening; and a powder lubricant feedingdevice having a feed passage extending through the attachment, a nozzlebeing arranged at one end of the feed passage, the nozzle protrudinginto the interior of the sleeve through the single molten metal feedingport opening; and wherein both powder lubricant and air are dischargedthrough the nozzle into the interior of the sleeve.
 5. A sleevelubricating mechanism as set forth in claim 4, in which the nozzleattached to the attachment is composed of a copper pipe having anadjustable length via cutting.
 6. A sleeve lubricating mechanism as setforth in claim 4, further comprising means for adjusting a sucking forceof the vacuum device and an air discharging pressure and capacity of thepowder feeding device.